The invention relates to a false-twist texturing unit for endless synthetic filaments, to the drive thereof and particularly to the manner of assembly of the drive elements.
False twist texturing units with electric motor drives are known. But in practice, they only have externally arranged motors. Federal Republic of Germany Patent 28 20 816 describes a spinning or twisting machine in which a row of spindles are operated by individual motors. That patent also shows a texturing machine. In that case, the drive motor is fastened externally of the unit on a base plate which is adapted to the existing conditions. The drive to the unit in that case is delivered by a toothed belt drive.
The external application of the drive motor has a number of disadvantages. In addition to the necessarily cantilevered construction which takes up a great deal of space, the relatively long drive belt is a great disadvantage, particularly with respect to the noise it produces. Since only one toothed belt is used, an additional tensioning roller must be installed. This requires the use of a total of four toothed discs or gears, which are subject to early wear due to the various deflections.
Another technical as well as economic disadvantage results from the above described construction of the unit. For repair of the unit, either upon replacement of a bearing, regeneration of the false twisting discs or replacement thereof, or replacement of the toothed belt, etc., the entire unit, including the motor, must be removed from the machine. In this case, various factors, such as wiring off the motor and adjustment of the unit with all its additional devices are affected not only upon the dismantling but also upon the assembly. This results in standstill times which lead to a drop in production.
In Federal Republic of Germany Published Application OS 26 07 920, a friction false twisting texturing unit is disclosed. The unit shown therein has three motors, with one of the motors being integrated into each set of discs. In addition to the extremely high financial expense of this construction, it is also unfeasible from a technical standpoint. Such a set of discs is used at speeds of rotation of up to 12,000 rpm and must travel free of imbalance. This is not possible with a rotating outer ring, as shown in FIG. 3 of that publication, and can be made possible in the case of FIG. 4 thereof only under very cumbersome and difficult conditions, as is clear to one skilled in the art. Furthermore, concentricity of the discs, which is indispensable for good quality of the yarn, cannot be obtained in the required quality. In the event of wear of only one disc, for instance, the entire set of discs, including the rotor, can no longer be used. The self contained structure furthermore has great difficulties inherent in it, both upon mounting and upon dismounting, even for a person skilled in the art.
Another disadvantage resides in synchronizing the three motors with respect to each other since the three sets of discs must not experience any differences in their speeds of rotation, as this would lead to start-up difficulties of the thread or poor quality yarn.